Static objects such as buildings, hangars, store houses or others are sometimes a convenient target for attacks, intended against the building itself, objects stored or human beings staying therein. In some cases, a cluster of buildings, possibly with vehicles in their vicinity, make a convenient target when hitting any of the buildings or targets will satisfy the attacker.
Of particular threat are weapons aimed against such targets, such as shaped charges. For example rocket-propelled grenade (RPG) having an explosive charge shaped so as to focus the effect of the explosive's energy once heating an object, thus utilizing the kinetic energy of the object to create significant effect. Focusing the energy enables such charges to create extensive damage to the hit object, such as demolishing or severely damaging buildings or parts thereof, initiating nuclear weapons, penetrating armor, or the like. For example, a rocket can penetrate a steel armor to a depth significantly larger, than the diameter of the charge, for example around 10 times larger. The operation principle of the rocket uses the Munroe or Neumann effect of focusing the blast energy by a hollow or void cut on a surface of explosive.
Some known protective measures include protective walls or conventional nets made of cross cables having predetermined strength and elasticity. Protective walls are expensive, take a long time to erect, are static and cannot be reused or easily fixed when hit. For protective nets to be effective, such nets have to be made of strong material that would stop the rocket, and are thus expensive, heavy and cumbersome to transport, hard to deploy and fold, and generally inconvenient to use.